<!DOCTYPE html>
<meta charset=utf-8>
<title>Test RequestAnimationFrame Timestamps are monotonically increasing</title>
<script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
<script>
  var lastRequestAnimationFrameTimestamp = 0;
  var requestAnimationFrameCount = 20;
  var currentCount = 0;

  // Test that all timestamps are always increasing
  // and do not ever go backwards
  function rafCallback(aTimestamp) {
    SimpleTest.ok(aTimestamp > lastRequestAnimationFrameTimestamp,
      "New RequestAnimationFrame timestamp should be later than the previous RequestAnimationFrame timestamp");
    lastRequestAnimationFrameTimestamp = aTimestamp;
    if (currentCount == requestAnimationFrameCount) {
      SimpleTest.finish();
    } else {
      currentCount++;
      window.requestAnimationFrame(rafCallback);
    }
  }

  window.requestAnimationFrame(rafCallback);
  SimpleTest.waitForExplicitFinish();
</script>
